The structure of the peptide chain is often modeled by simple amides and the structure of steroid hormones by acrolein. Recent evidence has indicated that the spectrum of these compounds may have been misinterpreted. With modern computers, ab initio quantum chemistry is now capable of predicting the excitation energy to the first few excited states of simple compounds within plus or minus 0.3 eV. In the proposed research we will use the best available procedures to predict the spectrum of N-methyl acetamide and acrolein. The theory of the electronic structure of the peptide linkage and of the enone group in steroids will then be re-evaluated.